Vacuum tube device



Oct. 29, 1940. HERZOG 2,219,925

VACUUM TUBE DEVI CE Filed Sept. 15, 1939 INV EN TOR.

ATTORNEY.

Patented Oct. 29, 1940 UNITED STATES PATENT OFFICE VACUUM TUBE DEVICE Application September 15, 1939, Serial No. 295,083 In Germany September 21, 1938 3 Claims.

This invention relates to vacuum tube devices, and more particularly to new and useful methods of and means for simplifying and improving such devices.

It has become common practice in the manufacture of vacuum tube devices to replace the heretofore usual glass stem by a plane member of glass or similar vitreous material and to seal the various lead-ins for the electrodes of such devices in this plane member at right angles thereto. After the different electrodes have been correctly attached to their respective lead-in conductors, the resultant assembly was placed in position within a suitable metallic container and the plane member of glass was sealed to this container. However, this method encounters certain disadvantages which particularly occur in the difficulty to maintain the lead-ins and the electrodes in their correct positions to each other 20 during the step of sealing the plane member to the metallic container, since the considerable heat required for the sealing operation unfortunately tends to soften this member with the result that the electrodes are laterally or otherwise displaced or even become so loose that they fall down into the container during the sealing operation.

It is an object of this invention to provide a method of and means for overcoming the above mentioned disadvantage in a simple and reliable manner. This is achieved according to the invention by the provision of a special supporting member of ceramic for the purpose of protecting the lead-in conductors against eventual displacement during the aforesaid sealing operation. This ceramic member or disc is perforated, that is, provided with small bores or apertures which coincide with the various lead-in conductors sealed in the plane disc of glass. This ceramic member is slid over the lead-ins before the electrodes are attached to their respective lead-ins and, of course, prior to the step in which the glass disc is sealed to the outer metallic container. In 45 accomplishing this latter step, the ceramic member serves not only as a heat insulator but also as an additional support for the lead-ins, the shoulders of which rest upon the upper surface of the glass disc. The lead-in conductors and 50 the electrodes are thus maintained in their correct positions relative to each other until the vacuum tube device has been finished.

My invention will be fully understood from the following description taken in conjunction 5 with the accompanying drawing, the single figure of which shows a sectional View of one embodiment of my invention.

With reference to the drawing, reference numeral I denotes a tube envelope which is assumed to be of metal to form the anode of an 5 electron discharge device. The open end of this envelope consists of an enlarged portion 2 followed by a flanged portion 3. The requisite number of electrode lead-in conductors 8 each having a shoulder formed by an enlarged end portion 6 10 are so sealed in the plane disc 5 that the enlarged end portions project above and below the opposite surfaces of the disc 5. A perforated member 4 of ceramic having a number of bores or apertures arranged so as to correspond to the 15 positions of the leads 6 in the disc 5 is slid over the conductors into abutment with the. shoulders B of the leads 6, whereupon the various electrodes of an electrode system 1 are attached to the corresponding lead-in conductors. The resultant assembly is then ready to be inserted into the envelope 1. The ceramic member 4 then loosely fits the enlarged portion 2 of the envelope I, while the disc 5 rests upon the flange 3. On sealing the disc 5 to the flange 3, the refractory member 4 simultaneously serves as a support for the electrodes and their lead-in conductors and as a heat insulating medium. The disc 5 is not subject to any stresses since the shoulders of the lead-in conductors fully rest on the ceramic member 4. It is thus possible to seal the disc 5 to the envelope l without running any risk that the heat applied to the sealing surface may introduce any changes to the desired and correct positions of the lead-ins or electrodes in the metallic vacuum envelope.

What is claimed is:

1. The method of manufacturing vacuum tube devices which comprises, sealing into a plane disc of vitreous material and at right angles thereto a number of lead-in conductors each having a shoulder formed by an enlarged end portion projecting below and above the opposite surfaces of the disc, sliding a perforated member of refractory insulation over the lead-in conductors into abutment with the shoulders thereof, attaching the various electrodes of a vacuum tube device to their respective lead-in conductors, placing the resultant assembly into a metallic tube envelope having an enlarged portion corresponding to the configuration of the perforated member of insulation and a flanged open end corresponding to the configuration of the plane disc, and sealing the plane disc of vitreous material to the flange of the metallic envelope.

2. As a product of manufacture, a vacuum tube device comprising, a metallic envelope having an enlarged cylindric end portion followed by a flange portion, a plane disc of vitreous material sealed to the flange of the said metallic envelope, a plurality of lead-in conductors each having a shoulder formed by an enlarged end portion projecting through and sealed in the said plane disc at right angles thereto, a perforated member of refractory insulation having holes therein for,

passage of said lead-in conductors therethrough loosely fitting the said enlarged cylindric end portion of the metallic envelope, and electrodes each attached to its respective lead-in conductor, the said perforated member being in abutment with the said shoulders to support said conductors and said electrodes.

3. A vacuum tube device according to claim 2, wherein said perforated member of refractory insulation. is made of a ceramic material.

ROBERT HERZOG. 

